Physiological studies and seawater nutrient analysis showed that the productivity of the macroalga Sargassum natans was significantly enhanced by higher N and P availability in neritic compared to oceanic waters of the western North Atlantic Ocean (17-400N).This manuscript is an author version with the final publication available at http://aslo.org/lo/ and may be cited as: Lapointe, B. E. (1995). A comparison of nutrient-limited productivity in Sargassum natans from neritic vs. oceanic waters of the western North Atlantic Ocean. Limnology and Oceanography, 40(3), 625-633.Florida Atlantic University. Harbor Branch Oceanographic Institute contribution #928.